When an alien substance such as dust is present near a focal plane of a lens of a camera, a shadow of the alien substance is reflected on a solid image sensing device. Such an alien substance is actually a fine substance of a size equal to or smaller than several tens μm. It is considered that the alien substance adheres to near the focal plane because dust enters the camera from the outside when the lens is replaced or, according to an operation of a shutter or a mirror in the camera, fine abrasion powder of resin or the like forming the shutter or the mirror is generated. When such dust enters between a cover glass for protection of the solid image sensing device and an optical filer such as an infrared cut filter or an optical low-pass filter (hereinafter, “LPF”) disposed in front of the cover glass, the camera has to be disassembled in order to remove the dust. Therefore, it is extremely effective to adopt a seal structure to prevent the dust from entering between the cover glass of the solid image sensing device and the optical filter.
However, in a case where dust adheres to a surface on a side of the optical filter opposed to the solid image sensing device and a surface on an opposite side, it is difficult to remove the dust because the dust is fine. In a case where a position to which the dust adheres is near the focal plane, there still remains a problem in that a shadow of the dust is clearly projected on the solid image sensing device.
In particular, in recent years, the number of pixels of a captured image has been increased in a lens replaceable digital single-lens reflex camera as well. A digital single-lens reflex camera of a 135 format (135 size) having a resolution of 10 million pixels is on the market. When the number of pixels increases to make it possible to obtain high-definition and clear images, there is an increasing demand that a photographed high-resolution image should be enlarged and displayed for confirmation. If the image of high resolution is enlarged and displayed, a shadow of an alien substance is conspicuous all the more. Thus, an alien substance adhering to near a focal plane of a lens of the camera is regarded as a problem.
Therefore, in order to solve such a problem, there is a camera in which a surface of a cover glass of a solid image sensing device or an outermost surface of a dust-proof structure is cleaned by a wiper (see Japanese Patent Application Laid-open No. 2003-018440). If such a constitution of such camera is adopted, it is possible to remove dust adhering to the surface of the cover glass of the solid image sensing device or the outermost surface of the dust-proof structure (e.g., a surface of an optical filter) without removing the lens and disassembling the camera.
However, in the constitution described in Japanese Patent Application Laid-open No. 2003-018440, since the surface of the cover glass of the solid image sensing device or the outermost surface of the dust-proof structure is rubbed by the wiper, it is likely that hard dust like metal powder scratches the surface of the cover glass of the solid image sensing device or the outermost surface of the dust-proof structure. In addition, since a mechanism for disposing the wiper is required, a size of the camera increases.
There is, therefore, a camera in which dust is removed from an object to be cleaned by a cohesive cleaning stick (Japanese Utility Model Application Publication No. Hei 05-085361 and Japanese Patent Application Laid-open No. 2003-220014). The camera uses the cohesive cleaning stick including a cleaning portion having both cushioning properties and cohesiveness with a cohesive member disposed at one end of a cylindrical member via a cushion material. Alternatively, the camera uses a cohesive cleaning stick with a rubber-based adhesive applied at one end of a cylindrical member. Dust adhering to a surface of a cover glass of a solid image sensing device or a surface of an optical filter is removed by the cleaning stick. In a case where cleaning is performed using such a cohesive cleaning stick, it is relatively easy to remove dust if an amount of dust adhering to the surface of the cover glass of the solid image sensing device or the surface of the optical filter is small. However, in a case where a large amount of dust dispersing over almost the entire area of the cover glass or the filter is removed, it is necessary to perform removal operation a large number of times because the cohesive cleaning stick has to be brought into contact with each piece of dust. This makes operation troublesome.
Japanese Patent Application Laid-open No. 2003-220014 describes cleaning performed by rotating a cohesive member having a substantially circular section. However, since it is impossible to bring the substantially circular cohesive member into contact with an alien substance adhering to a corner part of a quadrilateral, it is impossible to remove the alien substance adhering to the corner part. Moreover, if the cohesive member is rotated, it is likely to cause wiping unevenness. Since there are various sizes of a solid image sensing device (a 135 full size, an APS-C size, etc.), in order to make the cohesive member applicable to all the sizes, it is desirable to prepare cleaning portions of plural sizes such that a user can select one out of the cleaning portion appropriately and mount the cleaning portion on the cohesive member to perform cleaning.
However, as described above, it is necessary to form the cleaning portion coming into contact with an optical member with a soft member to prevent the cleaning portion from damaging the optical member. However, in a case where such a soft member can be replaced and is mounted on a hard support portion, it is likely that the cleaning portion comes off the support portion during cleaning work. If such a situation occurs, then it is likely that a tip of the hard support portion, from which the cleaning portion has come off, scratches a surface of a cover glass of the solid image sensing device or a surface of an optical filter.